Polished Concrete Glossary Terms and Definitions
- Abrasion resistance: Ability of a surface to resist being worn away by rubbing and friction.
- Abrasive pad: A circular pad, resembling a typical floor maintenance burnishing pad that has the capability of refining the concrete surface on a microscopic level that may or may not contain industrial-grade diamonds.? These pads are typically used for the maintenance and/or restoration of previously installed polished concrete flooring.
- Acid stain: A reactive solution of one or more metal salts stabilized by acid that produces coloration in a concrete substrate.
- Aggregate exposure: Grinding a concrete floor surface with bonded abrasives to achieve a specified class of exposed aggregate. These are classified as A, B, C and D with varying levels of exposed aggregate. (See Aggregate Exposure Chart)
Aggregate Exposure Chart
Class |
Name |
Approximate Surface Cut Depth* |
Appearance |
A |
Cream |
Very little |
Minimal exposure of fine aggregates or sands. High FF requirement is critical to achieving uniform appearance. |
B |
Fine Aggregate (Salt and Pepper) |
1/16 inch |
Fine aggregate exposure with little or no medium aggregate exposure at random locations |
C |
Medium Aggregate |
1/8 inch |
Medium aggregate exposure with little or no large aggregate exposure |
D |
Large Aggregate |
1/4 inch |
Large aggregate exposure with little or no fine aggregate exposure |
*Substrate mix design, finish, and flatness will affect appearance.
- Ambient temperature: The average or mean temperature of the surrounding air which comes into contact with the equipment or surface under testing.
- Aqueous solution: A solution in which the solvent is water. While water is often called the universal solvent, it only dissolves substances that are hydrophilic in nature.
- Bonded Abrasive: An abrasive medium that is held within a bonding that erodes away to expose the new abrasive medium as it is used.
- Binders: Liquid polymer modifying admixture that aids in the physical strength and bonding properties of mortars and concrete.
- Bonded Abrasive: An abrasive medium that is held within a bonding that erodes away to expose the new abrasive medium as it is used.
- Bonded abrasive polished concrete: The multi-step operation of mechanically grinding, honing,? and polishing a concrete floor surface with bonded abrasives to cut a concrete floor surface and to refine each cut to the maximum potential to achieve a specified level of CPC defined finished gloss.
- Bonding: Adhesion, cohesion, or both between multiple materials.
- Burnished polished concrete: The multi-step operation of mechanical friction-rubbing a concrete floor surface with or without waxes or resins to achieve a specified level of CPC defined finished gloss. This operation yields a less durable finish and requires more maintenance than bonded abrasive polished concrete.
- Burnisher: A variable speed, single or multiple rotating heads walk behind or ride on a machine that spins an abrasive pad, with or without bonded abrasives, at 1,200 rpm or higher.
- Burnishing: The act of using a high-speed burnisher affixed with an abrasive pad to further enhance the microscopic abrasion of the concrete surface to increase the finished gloss.
- Burnishing equipment: High-speed walk-behind or ride-on machines capable of generating 1000 to 2000 revolutions per minute and with sufficient head pressure of not less than 20 pounds to raise floor temperature by 20 degrees F.
- Compressive strength: The capacity of concrete to withstand loads tending to reduce the size (being pushed together) as opposed to tensile strength that makes materials elongate.
- Concrete dust: Silica containing particles that when disturbed becomes airborne and potentially harmful.
- Concrete slurry: A mixture of water and any finely divided insoluble material, such as Portland cement, slag, or clay in suspension.
- Concrete substrate😕 The ground below a slab, existing plain concrete paving, or a structural slab designed to carry loads.
- Crosshatch: A multi-directional pass/cut with grinding or polishing equipment.
- Curing compounds: A liquid applied to the surface of newly placed concrete that retards the evaporation of water and, if pigmented, reflects sunlight.
- Cut: The removal of a horizontal layer of a concrete surface with the use of mechanical equipment and optional liquid enhancers to expedite the process.
- Densifier: A combination of silicate and water-based compounds that react in the surface of the concrete to produce additional calcium silicate hydrate (CSH); silicates are combined with carrier compounds, most commonly sodium-, potassium-, or lithium-based to aid the process. Some products also contain siliconate.
- Diamond Tooling: Abrasive tools that contain industrial-grade diamonds within a bonded matrix (such as metallic, resinous, ceramic, etc) that are attached to rotating heads to refine the concrete substrate.
- The distinction of Image (DOI): A measure of how clearly a reflective image will appear on a reflective surface.
- Dye: A colorant for concrete that is applied and penetrates into the concrete while it is in solution and results in a stained appearance. Concrete dyes do not produce color via chemical reaction; they are usually a synthetic organic compound and can degrade when exposed to light or alkalinity.
- Dynamic Coefficient of Friction (DCOF): The ratio of the horizontal component of force applied to a body required to overcome resistance to movement when the body is already in motion divided by the vertical component of the weight of the body or force applied to the surface where movement occurs.
- Edge detailing: The act of blending or installing a contrasting border along the perimeter of the room(s) using a liquid coating.
- Edge grinding: Processing or grinding a floor to the vertical wall or edge in a way that mimics the aggregate exposure of the primary floor field.
- Edge polishing: The steps required by a polishing technician to process the concrete substrate along the perimeter of the room(s) to a finished gloss equal to that installed within the open areas of the room. These steps typically involve the same sequence of grits used by the polishing technician within the polishing process and typically are performed within the sequence of the grinder.
- Edge treatment: A defined border of a clear or pigmented coating that is applied around the perimeter of a room.
- Efflorescence: A generally white deposit formed when water-soluble compounds emerge in solution from concrete substrates and precipitate by a reaction such as carbonation or crystallize by evaporation.
- Field grinding: Processing or grinding the central areas of a floor surface.
- Field mock-up: An architectural concrete sample made using the same materials and methods proposed for the actual project. Often required for quality assurance on a large project, to ensure that architectural requirements and industry tolerances are met. The size should be sufficient to adequately demonstrate the full polishing process.
- Final film thickness: The depth of the film when wet (wet film thickness) and the final depth when dry (dry film thickness).
- Film-Forming Coating: A film-forming material which is designed to be a surface coating on concrete with a minimal film thickness of greater than 0.05 mils. which meets the OSHA requirements for slip resistance as tested by ASTM D2047 and stain resistance of ASTM D1308.
PART 1 – Typical Film Formers
PART 2 –Wax
PART 3 –Acrylics
PART 4 – Epoxy
PART 5 –Urethane
PART 6 –Polyaspartic
PART 7 –Methyl Methacrylates
PART 8 –Other film formers compatible with concrete
Finished Gloss
Processing a concrete floor surface to achieve a specified level of finished gloss prior to application of any protective treatment; Flat [ground], satin [honed], polished, and highly polished are measured in reflective clarity (DOI), and reflective sheen (specular gloss). Finished Gloss is classified as levels 1, 2, 3 and 4 with varying degrees of reflective clarity, and sheen. (see Finished Gloss Chart).
Finished Gloss Chart
Level |
Name |
Reflective Clarity |
Reflective Sheen |
Gloss Reading |
Grit |
|
1 |
Flat [Ground] |
Flat appearance with no to very slight diffused reflection |
0-10 |
None to very low |
n/a |
100 |
2 |
Satin [Honed] |
Matte appearance with or without slight diffused reflection |
10-25 |
Low to medium |
40-49 |
100-400 |
3 |
Polished |
Objects being reflected are not quite sharp and crisp but can be easily identified |
25-45 |
Medium to high |
50-59 |
400-800 |
4 |
Highly-Polished |
Objects being reflected are sharp and crisp as would be seen in a mirror-like reflection |
45-100 |
High to highest |
60-80 and above |
800 and higher |
- Flow rate: The volume of processed dust at any point in the collection system, measured in terms of cubic feet per minute (CFM).
- Form-release agents: Material used to prevent bonding of concrete to a surface.
- Glaze: A smooth shiny coating or finish.
- Gloss Measurement: A determination of specular gloss that could also incorporate distinction of image, haze, and Rspec.
- Gloss meter: A device that is capable of measuring specular gloss at 20, 60, or 80 degrees.
- Grinder: A multiple heads, rotating, walk behind or ride on machine, of various sizes and weights, with diamond tooling affixed to the heads for the purpose of grinding concrete. Excludes janitorial maintenance equipment.
- Grinding Stage: The steps of the polishing process that removes the concrete uniformly in preparation for the honing stage. This stage is typically the beginning for Class C and D specified floors and may meet the requirements for a level 1 specified gloss. This stage consists of any bonded abrasive that is 100 grit or lower.
- Grout: A thin mortar used for filling spaces; also: any of various other materials (as a mixture of cement and water or chemicals that solidify) used for a similar purpose.
- Grouting: The act of using a grout that is forced into the pore structure of the concrete substrate to fill surface imperfections.
- Haze: An optical effect caused by microscopic textures or residue on a surface.
- Head pressure: Determined by the combination of machine weight and a number of grinding heads touching the floor. Knowing the head pressure of a grinding machine aids in choosing the correct tooling.
- Honing Stage: The steps of the polishing process that refine the concrete in preparation for the polishing stage. This stage can sometimes be the beginning steps for Class B specified floors and may meet the requirements for a level 2 specified gloss. This stage consists of diamond tooling within the 100-400 grit range.
- Hybrid polished concrete: A multi-step operation, using either standard grinding / polishing equipment, lightweight equipment, high speed burnishing equipment, or a combination of, to combine the mechanical grinding, honing, and polishing process with the friction rubbing process by utilizing bonded abrasives, abrasive pads, or a combination of, to achieve the specified level of CPC defined finished gloss.
- Hybrid Tooling: Diamond tooling that combines metal bond and resin bond, or specially hardened resin that has the characteristics of both types of tooling.? These types of tools are typically used as either transitional tooling from metal bond tools to resin bond tools or as a first cut tool on smooth concrete surfaces.
- Laitance: A layer of weak material derived from cementitious material and aggregate fines either: (1) carried by bleeding to the surface or to internal cavities of freshly placed mixture; (2) separated from the mixture and deposited on the surface or internal cavities during placement of the mixture.
- Liquid Densifier: An Aqueous solution of Silicon Dioxide dissolved in one of the following Hydroxides that penetrates into the concrete surface and reacts with the Calcium Hydroxide to provide a permanent chemical reaction that hardens and densifies the wear surface of the cementitious portion of the concrete. All the below is the same chemistry varying only by the alkali used for solubility of the SiO2.
-
- Sodium Silicate
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- Potassium Silicate
-
- Lithium Silicate
- Alkalis solution of Colloidal Silicates or Silica
NOTE: The following products do not harden or densify the concrete.
-
- Siliconate is a synonym for Sodium Silicate that is solid without any water and therefore non-reactive in the reactions described above.
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- Colloidal Silica SiO2 that is suspended only in H2O is non-reactive as a densifier.
Siliconates are sometimes truncated descriptions for an Alkyl (organic) Alkali Metal Silicate which is water repellents and reacts in the acid form of CO2 (Carbon Dioxide) and H2O (Carbonic Acid). These might be used as an additive in Silicate Solutions for early water repelling of the densifiers
- Maximum refinement: The point in time when the diamond tool has refined the surface to the degree to which it no longer cuts or cuts very little under its current weight.
- Membrane curing: a process that involves the application of a liquid membrane-forming compound or covering with protective sheet material, both of which function as a barrier to restrict evaporation of water from concrete surfaces. NOTE- Potable water is applied after the finishing and prior to the application of the blankets/covering.
- Metal Bond Tooling: Diamond tooling that contains industrial grade diamonds with a metallic bonded matrix that is attached to rotating heads to refine the concrete substrate.? These tools are available in levels of a soft, medium, and hard metallic matrices that are matched with contrasting concrete substrates (i.e. hard matrix/soft concrete, medium matrix/medium concrete, soft matrix/hard concrete) and are typically used in the grinding and early honing stages of the polishing process.
- Mockup: A sample of products and procedures performed at the job site to establish a standard for visual appearance, skill and knowledge level of the craftsman, and overall procedures required to overcome imposed variables and install a polished concrete floor for a particular project.
- Mix design: The proportions of ingredients that use available materials to produce mortar or concrete of the required properties.
- Moisture: Moisture in concrete can be measured as a moisture vapor emission rate or MVER, and as in situ relative humidity, or RH. Just as concrete density and porosity affect the absorption of densifier and colorants, the porosity of a slab will also affect MVER and RH readings. The moisture level, in turn, can affect the vibrancy and staying power of topical color, the penetration of densifier, the clarity of shine, the strength development of concrete, and the appearance (differential cure marks) and level of efflorescence.
- Pass: The forward and backward motion with a grinder or burnisher along with a grid pattern of the concrete floor required to process the concrete into a specified finished gloss. One pass is typically forward and back within the same pathway.
- Pigmented Micro Stains: Fine pigment particles suspended in water-based silicate solution that penetrates concrete and reacts with calcium hydroxide to lock in color particles
- Polished Concrete – The act of changing a concrete floor surface, with or without aggregate exposure, to achieve a specified level of gloss using one of the listed classifications; Bonded Abrasive Polished Concrete, Burnished Polished Concrete, or Hybrid Polished Concrete.
- Polishing Process: The steps required by a polishing technician to transform the concrete substrate into a specified finished gloss. These steps may include a sequence of grits of bonded abrasives spanning the grinding, honing and polishing stages.
- Polishing Stage: The final stages of the polishing process that refine the concrete to the specified finished gloss level. This stage consists of diamond tooling that is 800 grit or higher.
- Pore Structure: The makeup of the voids in concrete that vary in size, location, and distance from each other, which may affect the chemicals used in the polishing process.
- Processing: The act of changing a concrete floor surface by means of a multi-step mechanical operation that involves cutting and/or refining the surface to the maximum potential with a bonded abrasive where each step cuts progressively finer microscopic peaks and valleys. Each step must be refined to its maximum potential in which the abrasive no longer cuts or cuts very little under its current weight and set variables.
- Refine: The act of changing the existing concrete surface by mechanical means by cutting and honing the surface to the desired finish.
- Reflective Clarity: The DOI (distinction of image) value of the degree of sharpness and crispness of the reflection of overhead objects when measured by a device in accordance with ASTM D5767.
- Reflective Sheen: The specular gloss value of the degree of gloss reflected from a surface, at specified angles of illumination, when measured by a device in accordance with ASTM D523-08.
- Repair Material: A product that is designed to repair cracks and or surface imperfections. The specified material must have sufficient bonding capabilities to adhere after the concrete surface has been polished and provide abrasion resistance equal to or greater than the surrounding concrete substrate.
- Resin bond tooling: Diamond tooling that contains industrial grade diamonds within a resinous bonded matrix (poly-phenolic, ester-phenolic, thermoplastic-phenolic) that is attached to rotating heads to refine the concrete substrate. Resin bond tooling is typically used for the later honing and polishing stages of the polishing process.
- Rspec: The peak gloss value over a very narrow-angle.
- Sealer – Semi Impregnating Stain Protection:? A film forming material which will penetrate into the polished and densified concrete leaving a protective surface film of fewer than 0.5 mils which meets the OSHA requirements for slip resistance as tested by ASTM D 20471, and stain resistance of ASTM D 13082.
- Sealer – Impregnating Stain Protection: Non-film forming stain and food resistant penetrating sealer designed to be applied to densified and polished concrete. The material must meet the requirements for slip resistance as tested by ANSI A137.1, and Stain resistance of ASTM D 13082.
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- ANSI A 137.1 Procedure for Dynamic Coefficient of Friction (DCOF) Testing
- ASTM D1308 Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
- Slurry: A thin mud or cement, or any fluid mixture of a pulverized solid within a liquid (usually water), often used as a convenient way of handling solids in bulk.
- Specular Gloss: A single measurement of gloss by shining a known amount of light at a surface within a specified angle of illumination and quantifying the reflectance. Specified angles of illumination are 20 degrees for gloss ranges higher than 70 GU, 60 degrees for gloss ranges between 10-70 GU, and 85 Degrees for gloss ranges below 10 GU.
- Stain (noun): A pronounced colored spot in the concrete caused by a material which is a soilant, discolorant or a reactant which changes the concrete surface resulting in an undesired appearance.
- Stain (verb): The deliberate action of applying a colored liquid material to change the appearance of the concrete surface. The products used can be acid stains,? pigmented water-based stains, or penetrating dyes.
- Stain Resistant: As defined in ASTM D 1308 – Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes.
- Static Coefficient of Friction (SCOF): The ratio of the horizontal component of force applied to a body that just overcomes the resistance to slipping to the vertical component of the weight of the object or force applied.
- Surface coated concrete: Surface coated concrete does not conform to the definition of polished concrete per the CPC. It is the operation of applying a film forming coating to a concrete floor surface to achieve a specified level of finished gloss. Durability depends on the quality of the chemical coating used, the amount of traffic across the floor, and floor maintenance.
- Surface profile: The advanced measurement of surface topography on a microscopic level of a concrete floor surface with metrology devices.
- Transition tooling: Diamond tooling that is used to refine the scratch pattern of metal bond tooling prior to the use of resin bond tooling in an effort to extend the life of resin bond tooling and to create a better foundation for the polishing process.
- Tribometer: An instrument or device specifically designed to measure the available level of traction upon a floor or walkway surface.
- Variables: An unlimited number of influential changes or pressures imposed upon the polishing technician during the polishing process. (ie weight of the machine, the linear speed of the grinder, diamond tooling head pressure, hardness of the concrete substrate, etc).
- Ventilation: Air renovation process of the premises to restrict the deterioration of its quality, from the point of view of its composition, which is carried out through outside air intake and the evacuation of the stale air.
- Wet Grinding: Mechanically grinding the surface using water as a cooling agent for the diamond tooling. The water acts as a lubricant and reduces friction, usually extending the life of the tooling. Wet grinding also aids in keeping silica dust particles from becoming airborne.